1. Field of the Invention
This invention relates generally to wireless telecommunications networks, and more specifically to a system and method for centralizing translation of a Special Dialing String ("SDS") and a Mobile Feature Code ("MFC") in a Home Location Register to permit consistent and/or customized translation of the SDS or MFC depending upon various subscriber and/or geographic factors.
2. Background
A typical wireless telecommunications network includes a large number of mobile switching centers, spread across a broad geographic area. Whenever a mobile subscriber places a call, a nearby mobile switching center receives the wireless signal for processing. As a mobile subscriber moves between different geographic locations, different mobile switching centers may receive the wireless signal and process the subscriber's call.
As a matter of convenience to mobile subscribers, many wireless telecommunications companies permit mobile subscribers to dial a telephone number using a special dialing string ("SDS"). An SDS is a shortened or abbreviated dialing string, often beginning with a symbol such as "*" or "#" and typically containing 3 digits (e.g., *123). When a mobile subscriber dials an SDS, a mobile switching center receives the SDS and then translates the received SDS into a number to be dialed (e.g., *123 may be translated to 555-1234). Similarly, many wireless telecommunications companies also support the use of mobile feature codes ("MFCs"). An MFC is similar to an SDS, but is used to control service features (e.g., call forwarding) from a mobile subscriber's handset.
In a typical wireless telecommunications system, translation of SDSs and MFCs occurs within the mobile switching center processing the mobile subscriber's call. Thus, for example, when a mobile subscriber in one geographic location dials *123, a mobile switching center in that same location performs the required SDS or MFC translation. In contrast, when the same mobile subscriber is in a different geographic location and dials the same SDS or MFC (e.g., *123), a different mobile switching center will likely process the call.
Because each mobile switching center independently translates SDSs into dialed numbers, it is possible that the same SDS will be translated into a different number to be dialed depending upon which mobile switching center performs the translation. For example, if a subscriber in one geographic location, such as Texas, dials *123, the Dallas mobile switching center may translate the call to dialed number 458-1440. Whereas, if a mobile subscriber in another geographic location, such as Washington, D.C., the Washington D.C. mobile switching center may translate the call to a different dial number such as 555-1212. For the same reason, it is also possible that different mobile switching centers will activate/de-activate different service features in response to the same MFC processed by the different mobile switching centers.
In order to alleviate inconsistent translation of SDSs/MFCs, each mobile switching center has to be independently programmed to translate received SDSs/MFCs. This requires considerable effort and expense. Furthermore, whenever the translation of an SDS into a number to be dialed is to be changed, the same change must be made in every mobile switching center.
Therefore, what is needed is a system and method to ensure consistent translation of SDSs/MFCs, without requiring independent programming or reprogramming of mobile switching centers. Furthermore, what is needed is the ability to customize dialing string translations. Customer(s) and/or geographic specific translations are needed for SDS translation and customer(s) specific translations are needed for MFC translation such that customized dialing strings can be used that may over-ride preexisting global translations.